Event Driven Development

Transcript

1. Event Driven Development Christopher Riley ConFoo 2018 1
2. Introduction
3. Introduction • Event sourcing 2
4. Introduction • Event sourcing • Event Driven Architecture 2
5. Introduction • Event sourcing • Event Driven Architecture • Task Based UI 2
6. Introduction • Event sourcing • Event Driven Architecture • Task Based UI • Event storming 2
7. What is an event? 2
8. What is an event? • Something which has happened in the past 3
9. What is an event? • Something which has happened in the past • Relevant to a domain expert 3
10. What is an event? • Something which has happened in the past • Relevant to a domain expert • Not technical 3
11. What is an event? • Something which has happened in the past • Relevant to a domain expert • Not technical • Raised in response to an input 3
12. Task based UI
13. A CRUD UI 4
14. A Task Based UI 5
15. Everything a company does is part of a process 5
16. Why are task based UI’s helpful to event based systems? 5
17. Event sourcing
18. A familiar model 6
19. Event sourcing example 7
20. What does an event sourced system actually look like? 7
21. Event sourcing architecture 8
22. Handling a command 9
23. Inside the model 10
24. Inside the model 11
25. Handling Events 12
26. Projections
27. Projections • Turn events into read models 13
28. Projections • Turn events into read models • Can be eventually consistent 13
29. Projections • Turn events into read models • Can be eventually consistent • Can be rebuilt 13
30. A projection 14
31. Process Managers
32. Process managers • Handle business logic around events 15
33. Process managers • Handle business logic around events • A state machine 15
34. Process managers • Handle business logic around events • A state machine • Keep track of failures 15
35. Process managers • Handle business logic around events • A state machine • Keep track of failures • Be careful with replays 15
36. A Process Manager 16
37. Event Driven Architecture
38. Event Driven Architecture 17
39. Cross System Process 18
40. Conclusions
41. Thanks • @giveupalready • https://github.com/carnage • https://carnage.github.io 19